> Non tech folk use stuff like [messengers] to send things
Yes, and tech folks too, but what about if you're not already connected friends? You don't want to invite your entire audience at a conference to send them slides.
You either need to already have a website and say "click on News and find the entry for today", have them type over some long URL with perfect accuracy, or use a link shortener to the same effect. It always requires having hosting, unless there exists file sharing services. That's the problem these things solve.
Also mind that there are size limits in most messengers on the order of a few hundred megabytes. You don't run into them that often, but whatcha gonna do when you do? A dedicated file sharing service that supports in the gigabytes range solves that situation as well.
